Weld filler additive and method of welding

ABSTRACT

A method of welding using a weld filler additive and a weld filler additive are provided. The method includes the step of welding the component with a filler additive comprising a sufficient amount of each of W, Co, Cr, Al, Ti, Mo, Fe, B, C, Nb, and Ni, the component including a hard-to-weld base alloy. The method further includes the step of forming an easy-to-weld target alloy on a surface of the component from the welding.

FIELD OF THE INVENTION

The present invention is generally directed to a weld filler and amethod of welding using a weld filler. More specifically, the presentinvention is directed to a nickel-based weld filler and a method ofwelding hard-to-weld alloy using a nickel-based weld filler.

BACKGROUND OF THE INVENTION

Gas turbines for power generation systems must satisfy the highestdemands with respect to reliability, power, efficiency, economy, andoperating service life. Modern high-efficiency combustion turbines havefiring temperatures that exceed about 2,300° F. (1,260° C.), and firingtemperatures continue to increase as demand for more efficient enginescontinues. Many components that form the combustor and “hot gas path”turbine sections are directly exposed to aggressive hot combustiongases. The use of coatings on turbine components such as combustors,combustion liners, combustion transition pieces, combustion hardware,blades (buckets), vanes (nozzles) and shrouds is important in commercialgas turbine engines.

Superalloy, such as GTD 111 and its serial alloys, have been largelyused in gas turbine industry due to their excellent mechanicalproperties, oxidization resistance and corrosion resistance. They,however, have poor weldability due to a tendency for liquation crackingand strain age cracking (SAC). Due to the poor weldability of GTD 111and its serial alloys, weld filler materials have been usually selectedto sacrifice mechanical properties to meet weldability requirements.

BRIEF SUMMARY OF THE INVENTION

In an exemplary embodiment, a weld filler additive is provided. The weldfiller additive includes a sufficient amount of each of W, Co, Cr, Al,Ti, Mo, Fe, B, C, Nb, and Ni that forms an easy-to-weld target alloy,when welded with a hard-to-weld base alloy having Ti greater than 2% byweight and gamma prime greater than 45% volume fraction.

In another exemplary embodiment, a method of welding a component isprovided. The method includes the step of welding the component with afiller additive comprising a sufficient amount of each of W, Co, Cr, Al,Ti, Mo, Fe, B, C, Nb, and Ni, the component including a hard-to-weldbase alloy having Ti greater than 2% by weight and gamma prime greaterthan 45% volume fraction. The method further includes the step offorming an easy-to-weld target alloy on a surface of the component fromthe welding.

Other features and advantages of the present invention will be apparentfrom the following more detailed description of the preferredembodiment, taken in conjunction with the accompanying drawings, whichillustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a method, according to an exemplary embodiment of thepresent disclosure.

FIG. 2 illustrates a method, according to an alternate embodiment of thepresent disclosure.

Wherever possible, the same reference numbers will be used throughoutthe drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description set forth below in connection with the appendeddrawings where like numerals reference like elements is intended as adescription of various embodiments of the disclosed subject matter andis not intended to represent the only embodiments. Each embodimentdescribed in this disclosure is provided merely as an example orillustration and should not be construed as preferred or advantageousover other embodiments. The illustrative examples provided herein arenot intended to be exhaustive or to limit the claimed subject matter tothe precise forms disclosed.

All numbers expressing quantities of ingredients and/or reactionconditions are to be understood as being modified in all instances bythe term “about”, unless otherwise indicated.

All percentages and ratios are calculated by weight unless otherwiseindicated. All percentages are calculated based on the total weight of acomposition unless otherwise indicated. All component or compositionlevels are in reference to the active level of that component orcomposition, and are exclusive of impurities, for example, residualsolvents or by-products, which may be present in commercially availablesources.

The articles “a” and “an,” as used herein, mean one or more when appliedto any feature in embodiments of the present invention described in thespecification and claims. The use of “a” and “an” does not limit themeaning to a single feature unless such a limit is specifically stated.The article “the” preceding singular or plural nouns or noun phrasesdenotes a particular specified feature or particular specified featuresand may have a singular or plural connotation depending upon the contextin which it is used. The adjective “any” means one, some, or allindiscriminately of whatever quantity.

The term “at least one,” as used herein, means one or more and thusincludes individual components as well as mixtures/combinations.

The term “comprising” (and its grammatical variations), as used herein,is used in the inclusive sense of “having” or “including” and not in theexclusive sense of “consisting only of.”

The term “hard-to-weld alloy (and its variations)”, as used herein,means an alloy, having Al %>−½Ti%+3, where Al % is weight percent ofaluminum and Ti % is weight percent of titanium.

The term “easy-to-weld alloy (and its variations)”, as used herein,means an alloy, having Al %≤−½Ti %+3, where Al % is weight percent ofaluminum and Ti % is weight percent of titanium.

The term “buttering”, as used herein, means a process of applying a weldfiller additive to a hard-to-weld alloy to be transformed into aneasy-to-weld alloy so that additional easy-to-weld or hard-to-weld alloycan be deposited onto the easy-to-weld alloy.

As used herein, “GTD 111” refers to an alloy including a composition, byweight, of about 3.5-4.1% tungsten, about 9-10% cobalt, about 13.7-14.3%chromium, about 2.8-3.2% aluminum, about 2.4-3.1% of tantalum, about4.7-5.1% titanium, about 1.4-1.7% molybdenum, about 0.35% of iron, about0.005-0.02% of boron, about 0.08-0.12% of carbon and a balance ofnickel.

In one embodiment, the present invention enables a fusion weld without acrack.

With reference to FIG. 1, a component 100 is provided. The component 100includes a hard-to-weld base alloy 101 including a surface 107 and atreatment area 108. The treatment area 108 may include a crack, defect,or area removed, machined, or otherwise prepared for treatment. Inanother embodiment, the hard-to-weld base alloy 101 may have a pluralityof treatment area 108. An energy source 103 is placed to provide energyto melt a portion of filler additive 102 and a portion of thehard-to-weld base alloy 101. A melted portion 105 of the filler additive102 and the hard-to-weld base alloy 101 combines in a molten mix zone109, which solidifies to form a layer of easy-to-weld target alloy 106to fill in the treatment area 108. The treated component 100 iscrack-free weld metal and has a mechanical property of the easy-to-weldtarget alloy 106.

In an embodiment, the filler additive 102 may include a sufficientamount of each of W, Co, Cr, Al, Ti, Mo, Fe, B, C, Nb, and Ni that formsan easy-to-weld target alloy 106, when welded with a hard-to-weld basealloy 101 having Ti greater than 2% by weight and more than 45% gammaprime in volume fraction.

In one embodiment, the hard-to-weld alloy 101 according to the presentdisclosure may include a composition, by weight, of about 3.5-4.3%tungsten, about 9.0-10% cobalt, about 13.7-14.3% chromium, about2.8-3.9% aluminum, about 2.4-3.6% tantalum, about 3.4-5.1% titanium,about 1.4-1.7% molybdenum, about 0.35% of iron, about 0.005-0.02% ofboron, about 0.08-0.12% carbon, about 0-1.75% niobium and a balance ofnickel.

In one embodiment, the easy-to-weld alloy 106 according to the presentdisclosure may include a composition, by weight, of about 1.3-2.2%tungsten, about 18.5-19.5% cobalt, about 20.5-22.8% chromium, about1.6-2.65% aluminum, about 0.95-2.4% titanium, about 0.9-1.1% molybdenum,about 0.35% of iron, about 0.002-0.01% of boron, about 0.08-0.15%carbon, about 1.25-4.75% niobium and a balance of nickel.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include tungsten , by weight, about 0.05-2.0%, about0.1-1.9%, about 0.25-1.25%, about 0.5-1.5%, or about 1%, includingincrements, intervals, and sub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include cobalt, by weight, about 20-26%, about 21-25%,about 22-24%, or about 23%, including increments, intervals, andsub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include chromium, by weight, about 20-35%, about 22-33%,about 24-31%, or about 26-29%, including increments, intervals, andsub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include aluminum, by weight, about 0.5-3.5%, about 1-3%,about 1.5-2.5%, or about 2%, including increments, intervals, andsub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include titanium, by weight, about 0-2.5%, about 0.5-2%,or about 1-1.5%, including increments, intervals, and sub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, for molybdenum, may be, by weight, about 0-2.5%, about0.5-2%, or about 1-1.5%, including increments, intervals, and sub-rangetherein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include iron, by weight, about 0-1.0%, about 0.25-0.75%,or about 0.5%, including increments, intervals, and sub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include boron, by weight, about 0-0.02%, about0.005-0.015%, or about 0.01%, including increments, intervals, andsub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include carbon, by weight, about 0.01-0.15%, or about0.005-0.01%, or about 0.01%, including increments, intervals, andsub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include niobium, by weight, about 1.0-8.0%, about2.0-7.0%, about 3.0-6.0%, or about 4.0-5.0%, including increments,intervals, and sub-range therein.

In one embodiment, the filler additive 102, according to the presentdisclosure, may include a balance of nickel.

In one embodiment, the filler additive 102 may include a sufficientamount of each of W, Co, Cr, Al, Ti, Mo, Fe, B, C, Nb, and Ni that formsan easy-to-weld target alloy 106 comprising, by weight, about 0.05-2.0%of tungsten, about 20-26% of cobalt, about 20-35% of chromium, 0.5-3.5%of aluminum, about 0-2.5% of titanium, about 0-2.5% of molybdenum, about0-1.0% of iron, about 0-0.02% of boron, about 0.01-0.15% of carbon,about 1.0-4.0% of niobium, and a balance of nickel.

In another embodiment, the filler additive 102 may include a sufficientamount of each of W, Co, Cr, Al, Ti, Mo, Fe, B, C, Nb, and Ni that formsan easy-to-weld target alloy 106 comprising, by weight, about 0.05-2.0%of tungsten, about 20-26% of cobalt, about 20-35% of chromium, 0.5-3.5%of aluminum, about 0-2.5% of titanium, about 0-2.5% of molybdenum, about0-1.0% of iron, about 0-0.02% of boron, about 0.01-0.15% of carbon,about 4.0-8.0% of niobium, and a balance of nickel.

Using the same method stated above, it is also possible to obtainanother novel composition of filler additive to form the easy-to-weldtarget alloy including a composition, by weight, of about 1.8-2.2%tungsten, about 18.5-19.5% cobalt, about 22.2-22.8% chromium, about1.6-1.8% aluminum, about 2.2-2.4% titanium, about 0.15% molybdenum,about 0.35% of iron, about 0.002-0.008% of boron, about 0.08-0.12%carbon, about 1.25-1.45% niobium and a balance of nickel, or an alloyincluding a composition, by weight, of about 1.3-1.6% tungsten, about18.5-19.5% cobalt, about 20.5-21.1% chromium, about 2.55-2.65% aluminum,about 0.95-1.05% titanium, about 0.9-1.1% molybdenum, about 0.35% ofiron, about 0-0.01% of boron, about 0.12-0.15% carbon, about 4.65-4.75%niobium and a balance of nickel, when welded with a hard-to-weld basealloy having Ti greater than 2% by weight, such as GTD 111 including acomposition, by weight, of about 3.5-4.1% tungsten, about 9-10% cobalt,about 13.7-14.3% chromium, about 2.8-3.2% aluminum, about 2.4-3.1% oftantalum, about 4.7-5.1% titanium, about 1.4-1.7% molybdenum, about0.35% of iron, about 0.005-0.02% of boron, about 0.08-0.12% of carbonand a balance of nickel or a GTD111's serial alloy including acomposition, by weight, of about 4.0-4.3% tungsten, about 9.0-9.9%cobalt, about 13.7-14.3% chromium, about 3.5-3.9% aluminum, about 3.6%of tantalum, about 3.4-3.8% titanium, about 1.4-1.7% molybdenum, about0.35% of iron, about 0.005-0.02% of boron, about 0.08-0.12% of carbonand a balance of nickel.

In one embodiment, the filler additive 102 may include a composition, byweight, of about 0.05-2.0% of tungsten, about 20-26% of cobalt, about20-35% of chromium, 0.5-3.5% of aluminum, about 0-2.5% of titanium,about 0-2.5% of molybdenum, about 0-1.0% of iron, about 0-0.02% ofboron, about 0.01-0.15% of carbon, about 1.0-4.0% of niobium, and abalance of nickel.

In another embodiment, the filler additive 102 may include acomposition, by weight, of about 0.05-2.0% of tungsten, about 20-26% ofcobalt, about 20-35% of chromium, 0.5-3.5% of aluminum, about 0-2.5% oftitanium, about 0-2.5% of molybdenum, about 0-1.0% of iron, about0-0.02% of boron, about 0.01-0.15% of carbon, about 4.0-8.0% of niobium,and a balance of nickel.

In another embodiment, the filler additive 102 may include acomposition, by weight, of about 1.05-1.40% of tungsten, about22.55-24.0% of cobalt, about 25.80-26.45% of chromium, 1.05-1.20% ofaluminum, about 1.10-1.25% of titanium, about 0-0.35% of iron, about0.08-0.10% of carbon, about 1.75-2.10% of niobium, and a balance ofnickel.

In another embodiment, the filler additive 102 may include acomposition, by weight, of about 0.35-0.55% of tungsten, about22.55-23.60% of cobalt, about 23.40-24.05% of chromium, 2.40-2.45% ofaluminum, about 0.65-0.85% of molybdenum, about 0-0.35% of iron, about0-0.01% of boron, about 0.08-0.10% of carbon, about 6.60-6.80% ofniobium, and a balance of nickel.

In another embodiment, the filler additive 102 may include acomposition, by weight, of about 0.85-1.30% of tungsten, about22.55-23.65% of cobalt, about 25.80-26.45% of chromium, 0.75-0.90% ofaluminum, about 1.65-1.80% of titanium, about 0-0.35% of iron, about0.01-0.11% of boron, about 0.08-0.12% of carbon, about 1.10-1.35% ofniobium, and a balance of nickel.

In another embodiment, the filler additive 102 may include acomposition, by weight, of about 0.10-0.45% of tungsten, about22.55-23.65% of cobalt, about 23.40-24.05% of chromium, 2.10-2.15% ofaluminum, about 0.65-0.85% of molybdenum, about 0-0.35% of iron, about0-0.01% of boron, about 0.08-0.13% of carbon, about 5.95-6.05% ofniobium, and a balance of nickel.

In an embodiment, the filler additive 102 is a nickel-based alloy. Thefiller additive 102 may be fabricated into a powder, stick, wire, rod ora combination thereof.

In one embodiment, the hard-to-weld base alloy 101 may include acomposition, by weight, of about 3.5-4.1% tungsten, about 9-10% cobalt,about 13.7-14.3% chromium, about 2.8-3.2% aluminum, about 2.4-3.1% oftantalum, about 4.7-5.1% titanium, about 1.4-1.7% molybdenum, about0.35% of iron, about 0.005-0.02% of boron, about 0.08-0.12% of carbonand a balance of nickel.

In another embodiment, the hard-to-weld base alloy 101 may include acomposition, by weight, of about 4.0-4.3% tungsten, about 9.0-9.9%cobalt, about 13.7-14.3% chromium, about 3.5-3.9% aluminum, about 3.6%of tantalum, about 3.4-3.8% titanium, about 1.4-1.7% molybdenum, about0.35% of iron, about 0.005-0.02% of boron, about 0.08-0.12% of carbon,about 1.55-1.75% of niobium and a balance of nickel

In another embodiment, the hard-to-weld base alloy 101 may be GTD 111 orits serial alloys.

In one embodiment, the easy-to-weld target alloy 106 may include, byweight, about 1.8-2.2% tungsten, about 18.5-19.5% cobalt, about22.2-22.8% chromium, about 1.6-1.8% aluminum, about 2.2-2.4% titanium,about 0.15% molybdenum, about 0.35% of iron, about 0.002-0.008% ofboron, about 0.08-0.12% carbon, about 1.25-1.45% niobium and a balanceof nickel.

In another embodiment, the easy-to-weld target alloy 106 may include, byweight, about 1.3-1.6% tungsten, about 18.5-19.5% cobalt, about20.5-21.1% chromium, about 2.55-2.65% aluminum, about 0.95-1.05%titanium, about 0.9-1.1% of molybdenum, about 0.35% of iron, about0-0.01% of boron, about 0.12-0.15% carbon, about 4.65-4.75% niobium anda balance of nickel.

With reference to FIG. 2, a component 100 is provided. The component 100includes a first hard-to-weld base alloy 201 and second hard-to-weldbase alloy 202. An energy source 103 is arranged to provide energy tomelt a portion of filler additive 102 and a portion of the firsthard-to-weld base alloy 201 and the second hard-to-weld base alloy 202.A melted portion 105 from the molten mix zone 109 of the filler additive102 and the hard-to-weld base alloys 201 and 202 forms a layer of targetalloy 204 to create a fusion line 203 between the hard-to-weld basealloys 201 and 202. In one embodiment, the treated component 100 iscrack-free weld metal.

In an embodiment, the first hard-to-weld base alloy 201 may include amaterial that is the same as a material of the second hard-to-weld basealloy 202. In another embodiment, the base alloy includes a materialthat is dissimilar from a material of the second hard-to-weld base alloy202. The first hard-to-weld base alloy 201 may be GTD 111 or its serialalloys. The second hard-to-weld base alloy 202 may be GTD 111 or itsserial alloys.

In one embodiment, a method includes the step of welding the componentwith a filler additive comprising a sufficient amount of each of W, Co,Cr, Al, Ti, C, Nb, and Ni, the component including a base alloy. Themethod further includes the step of forming a target alloy on a surfaceof the component from the welding. In an embodiment, the filler additivemay be fusion welded with the hard-to-weld base alloy to form theeasy-to-weld target alloy. The easy-to-weld target alloy may be weldedwith the base alloy and the filler additive using a gas tungsten arcwelding process or a laser welding process plus additive powder orfiller. The method further includes the step of applying an alloy to thesurface to fill the weld groove and finish welding process, wherein thealloy is selected from the group consisting of an additional targetalloy, another filler additive, and combinations thereof.

In some embodiments, a weld filler additive is buttered to a basehard-to-weld alloy to create a layer of an easy-to-weld alloy so thatadditional easy-to-weld or hard-to-weld alloy can be welded onto thelayer formed from the buttering with the filler additive to fill in atreatment area.

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. A weld filler additive comprising: a sufficientamount of each of W, Co, Cr, Al, Ti, Mo, Fe, B, C, Nb, and Ni that formsan easy-to-weld target alloy, when welded with a hard-to-weld base alloyhaving Ti greater than 2% by weight and gamma prime is greater than 40%volume fraction.
 2. The weld filler additive according to claim 1comprises an alloy comprising, by weight, about 0.05-2.0% of tungsten,about 20-26% of cobalt, about 20-35% of chromium, 0.5-3.5% of aluminum,about 0-2.5% of titanium, about 0-2.5% of molybdenum, about 0-1.0% ofiron, about 0-0.02% of boron, about 0.01-0.15% of carbon, about 1.0-8.0%of niobium, and a balance of nickel.
 3. The weld filler additiveaccording to claim 1 comprises an alloy comprising, by weight, about1.05-1.40% of tungsten, about 22.55-24.0% of cobalt, about 25.80-26.45%of chromium, 1.05-1.20% of aluminum, about 1.10-1.25% of titanium, about0-0.35% of iron, about 0.08-0.10% of carbon, about 1.75-2.10% ofniobium, and a balance of nickel.
 4. The weld filler additive accordingto claim 1 comprises an alloy comprising, by weight, about 0.35-0.55% oftungsten, about 22.55-23.60% of cobalt, about 23.40-24.05% of chromium,2.40-2.45% of aluminum, about 0.65-0.85% of molybdenum, about 0.35% ofiron, about 0-0.01% of boron, about 0.08-0.10% of carbon, about6.60-6.80% of niobium, and a balance of nickel.
 5. The weld filleradditive according to claim 1, the easy-to-weld target alloy comprises,by weight, about 1.8-2.2% tungsten, about 18.5-19.5% cobalt, about22.2-22.8% chromium, about 1.6-1.8% aluminum, about 2.2-2.4% titanium,about 0.15% molybdenum, about 0.35% of iron, about 0.002-0.008% ofboron, about 0.08-0.12% carbon, about 1.25-1.45% niobium and a balanceof nickel.
 6. The weld filler additive according to claim 1, theeasy-to-weld target alloy comprises, by weight, about 1.3-1.6% tungsten,about 18.5-19.5% cobalt, about 20.5-21.1% chromium, about 2.55-2.65%aluminum, about 0.95-1.05% titanium, about 0.9-1.1% of molybdenum, about0.35% of iron, about 0-0.01% of boron, about 0.12-0.15% carbon, about4.65-4.75% niobium and a balance of nickel.
 7. The weld filler additiveaccording to claim 1, the hard-to-weld base alloy comprises by weight,about 3.5-4.1% tungsten, about 9-10% cobalt, about 13.7-14.3% chromium,about 2.8-3.2% aluminum, about 2.4-3.1% of tantalum, about 4.7-5.1%titanium, about 1.4-1.7% molybdenum, about 0.35% of iron, about0.005-0.02% of boron, about 0.08-0.12% of carbon and a balance ofnickel.
 8. The weld filler additive according to claim 1, thehard-to-weld base alloy comprises by weight, about 4.0-4.3% tungsten,about 9.0-9.9% cobalt, about 13.7-14.3% chromium, about 3.5-3.9%aluminum, about 3.6% of tantalum, about 3.4-3.8% titanium, about1.4-1.7% molybdenum, about 0.35% of iron, about 0.005-0.02% of boron,about 0.08-0.12% of carbon, about 1.55-1.75% of niobium and a balance ofnickel.
 9. The weld filler additive according to claim 1 is in a formselected from the group consisting of powder, stick, wire, rod, andcombinations thereof
 10. A method of welding a component, the methodcomprising: welding the component with a filler additive comprising asufficient amount of each of W, Co, Cr, Al, Ti, Mo, Fe, B, C, Nb, andNi, the component including a hard-to-weld base alloy having Ti greaterthan 2% by weight and gamma prime is greater than 40% volume fraction;and forming an easy-to-weld target alloy on a surface of the componentfrom the welding.
 11. The method according to claim 10, wherein thefiller additive comprises an alloy comprising, by weight, about0.05-2.0% of tungsten, about 20-26% of cobalt, about 20-35% of chromium,0.5-3.5% of aluminum, about 0-2.5% of titanium, about 0-2.5% ofmolybdenum, about 0-1.0% of iron, about 0-0.02% of boron, about0.01-0.15% of carbon, about 1.0-8.0% of niobium, and a balance ofnickel.
 12. The method according to claim 10, wherein the filleradditive comprises an alloy comprising, by weight, about 1.05-1.40% oftungsten, about 22.55-24.0% of cobalt, about 25.80-26.45% of chromium,1.05-1.20% of aluminum, about 1.10-1.25% of titanium, about 0-0.35% ofiron, about 0.08-0.10% of carbon, about 1.75-2.10% of niobium, and abalance of nickel.
 13. The method according to claim 10, wherein thefiller additive comprises an alloy comprising, by weight, about0.35-0.55% of tungsten, about 22.55-23.60% of cobalt, about 23.40-24.05%of chromium, 2.40-2.45% of aluminum, about 0.65-0.85% of molybdenum,about 0.35% of iron, about 0-0.01% of boron, about 0.08-0.10% of carbon,about 6.60-6.80% of niobium, and a balance of nickel.
 14. The methodaccording to claim 10, the easy-to-weld target alloy comprises, byweight, about 1.8-2.2% tungsten, about 18.5-19.5% cobalt, about22.2-22.8% chromium, about 1.6-1.8% aluminum, about 2.2-2.4% titanium,about 0.15% molybdenum, about 0.35% of iron, about 0.002-0.008% ofboron, about 0.08-0.12% carbon, about 1.25-1.45% niobium and a balanceof nickel.
 15. The method according to claim 10, the easy-to-weld targetalloy comprises, by weight, about 1.3-1.6% tungsten, about 18.5-19.5%cobalt, about 20.5-21.1% chromium, about 2.55-2.65% aluminum, about0.95-1.05% titanium, about 0.9-1.1% of molybdenum, about 0.35% of iron,about 0-0.01% of boron, about 0.12-0.15% carbon, about 4.65-4.75%niobium and a balance of nickel.
 16. The method according to claim 10,the hard-to-weld base alloy comprises by weight, about 3.5-4.1%tungsten, about 9-10% cobalt, about 13.7-14.3% chromium, about 2.8-3.2%aluminum, about 2.4-3.1% of tantalum, about 4.7-5.1% titanium, about1.4-1.7% molybdenum, about 0.35% of iron, about 0.005-0.02% of boron,about 0.08-0.12% of carbon and a balance of nickel.
 17. The methodaccording to claim 10, the hard-to-weld base alloy comprises by weight,about 4.0-4.3% tungsten, about 9.0-9.9% cobalt, about 13.7-14.3%chromium, about 3.5-3.9% aluminum, about 3.6% of tantalum, about3.4-3.8% titanium, about 1.4-1.7% molybdenum, about 0.35% of iron, about0.005-0.02% of boron, about 0.08-0.12% of carbon, about 1.55-1.75% ofniobium and a balance of nickel.
 18. The method according to claim 10,wherein the easy-to-weld target alloy is welded with the hard-to-weldbase alloy and the filler additive using a gas tungsten arc weldingprocess or a laser welding process plus additive powder or filler. 19.The method according to claim 10, wherein the filler additive is in aform selected from the group consisting of powder, stick, wire, rod, andcombinations thereof
 20. The method according to claim 10, furthercomprising applying an easy-to-weld alloy to the surface, the alloybeing selected from the group consisting of an additional target alloy,another filler additive, and combinations thereof.